Behavior of a Heat-Protective Material Based on Al.sub.2O.sub.3 and SiO.sub.2 Fibers under Exposure to Concentrated Solar Energy Flux

The paper presents the results of testing a heat-protective material based on Al.sub.2O.sub.3 and SiO.sub.2 fibers under exposure to a concentrated solar energy flux and highly non-uniform thermal and light field conditions. Avariation in the material structure and morphology depending on the heat treatment temperature is shown. The material retains its properties during extended exposure to temperatures of 1,600 - 1,700°C due to the formation of a stable mullite and [alpha]-Al.sub.2O.sub.3 structure. Above the mullite melting point (~1,840°C), the material undergoes deformation and melting, and loses its physical, mechanical, and thermal insulation properties.